Most headlamps that are used on bicycles are intended to be attached to the tubular handlebar of the bicycle. In a conventional bicycle, the handlebar includes a crosspiece that is oriented in a direction perpendicular to the frame of the bicycle. Typically, a bicycle headlamp is designed to be attached to this crosspiece so that it projects a beam of light in the forward direction of the bicycle.
Recently, aerodynamically styled handlebars have become popular. Quite often, these types of handlebars do not have a crosspiece which is perpendicular to the direction of movement of the bicycle. Rather, all of the various sections of the handlebar are contoured to fit the rider's profile, and do not offer a suitable location for mounting a headlamp that is designed to be attached to a perpendicular crosspiece. As a result, if a headlamp of this type is mounted to the handlebar, its beam points in a direction other than the forward direction of the bicycle.
There are some headlamps available that include a swivel mount to allow the lamp to be rotated so that it always points in the forward direction of the bicycle, regardless of the orientation of the mounting clamp itself. These types of headlamps are typically attached to the bicycle handlebar with the use of screws, or other mechanisms which require tools. As a result, it is not convenient for the bicycle rider to easily attach and remove the headlamp from the handlebar. For example, if it is necessary to perform repairs upon the chain or rear tire of the bicycle during nighttime riding, it is desirable for the rider to be able to remove the headlamp from the handlebar and place it near the rear of the bicycle while the repairs are being carried out. When the removal and remounting requires tools, however, the rider is not inclined to carry out this action in addition to the necessary repairs.
To facilitate removal, some bicycle headlamps are comprised of two separable assemblies, a mounting assembly and the headlamp itself. These systems enable the headlamp to be removed and located at a convenient position for effecting repairs. However, the mounting assembly still is attached to the handlebar by means of screws or the like, so that it is not readily removable from the bicycle without tools. It is not uncommon for a bicycle rider to own two or more different bicycles, for example, for different riding conditions. If the rider desires to be able to readily mount the headlamp on either of the two bicycles, it is necessary to obtain a second mounting assembly, so that each bicycle has its own, permanently attached mounting assembly. This type of system is not totally acceptable, because of the cost associated with a second mounting assembly and the unsightliness of having a mounting assembly attached to the bicycle when the headlamp is not in use.
Further along these lines, bicycle headlamps are typically designed for a single type of riding situation. For reasons of affordability, the majority of the headlamps provide low power lighting, which is suitable for most on-road riding situations. These types of headlamps contain internal batteries such as dry cells or rechargeable Ni-Cad cells which must be removed from the headlamp for charging. Some riding situations, such as off-road riding, have higher power lighting requirements. Headlamps designed for this purpose may have an external power source, such as a battery pack or a generator driven by the bicycle wheel. Typically, a headlamp designed for low-power requirements cannot be adapted to accommodate a high-power lighting situation. It is desirable, therefore, to provide a single headlamp which can be readily adapted for either type of lighting requirement.
Another concern that relates to of headlamps for bicycles is the location of the center of gravity of the headlamp relative to the mounting point. In many headlamp designs, the headlamp is in a cantilevered relationship with respect to the handlebar. In these types of designs, the center of gravity of the headlamp is not aligned with the handlebar or other mounting point. When the bicycle undergoes an impact, such as the type that is typically encountered in off-road riding, the force of the impact will cause the cantilevered mounting arrangement to rotate about the axis of the handlebar. Consequently, the headlamp might be pointing in a downward direction, rather than forwardly of the bicycle. As a result, the appropriate area will not be lighted and the rider will be forced to remove his hand from the handlebar and realign the position of the headlamp, posing an inconvenience and a safety hazard.